How much does it fit this denim pants?

2 years ago, I bought this pants 30"
definitely the size of the pants was 30" but it seems like 28".
so I had to return it.

Tech Specs:

Material:

[Black indigo stretch] 98% cotton, 2% Lycra; [Tinted Stretch, Overdyed Black] 99% cotton, 1% Lycra; [Blue] cotton 

Fit:

slim 

Inseam:

33 in 

Cuff Width:

14 in 

Waist:

belt loops 

Pockets:

2 front, 2 back 

Fly:

zipper 

Recommended Use:

streetwear 

Manufacturer Warranty:

1 year